John mclean



rares JOHN MCLEAN, OF NEV YORK, N. Y.

BICYCLE.

SPECIFICATION forming' part Of Letters Patent NO. 604,07 3, dated May 17, 1898.

Application led October 21, 1897. Serial No. 655,986. (No model.) 2

To a/ZZ wtont it may concern,.-

Beit known that I, JOHN MoLEAN, a citizen of the United States, residing in the city and county of New York, in the State of New York, have invented a certain new and useful Improvement in Bicycles, of which the following is a specification.

My improvement applies to that class of bicycles in which a longitudinal shaft with bevel-gears is employed to communicate the rotary motion from the pedal-shaft to the rear wheel, such shaft extending through a longitudinal tubular portion of the frame.

I form a strong and conveniently operable clamp connection at the junction of such frame-piece with the ordinary short cross-tube which incloses the crank-shaft, and I provide convenient means in connection therewith for adjustingits position and for removing it and replacing it when required. The improvement allows me by such change of position of the framing to not only vary the engagement of the gears, but also by a little labor to change the gearing by substituting higher or lower gears at will.

The accompanying drawings form a part of this specification and represent what I consider the best means of carrying out this invention.

Figure 1 (near the bottom of the sheet) is a general side elevation, on a small scale, showing the whole of that portion of the bicycle to which the invention relates. Fig. 2 is a plan View, on a larger scale, with certain upper portions broken away. The casings which inclose the gears are in horizontal section in the plane of the respective axes. The remaining figures are on a still larger scale. Fig. 3 is a plan View, partly in horizontal section,of parts at and adjacent to the rearwheelhub. Fig. 4 is a corresponding plan view and `horizontal section show-*ing the parts at and near the crank-axle. Fig. 5 is a side elevation of certain parts corresponding to Fig. if Fig. 6 isa side elevation of certain parts corresponding to Fig. 3. Fig. 7 is a vertical cross-section on the line 7 7 in Fig. 6.

Similar letters of reference indicate corresponding parts in all the iigures where they appear.

Ais the ordinary short cross-tube, strongly supported in the frame, and which serves to support the crank-shaft, with the ordinary or any suitable arrangement of antifrictionballs in each end.

B is the crank-shaft, turned by cranks B2 B2 and pedals B3 B3 in the ordinary and long-approved manner.

B' is a bevel gear-wheel, keyed or otherwise iirmly secured on the shaft B. Its teeth should be nicely out, and its conicity should be adapted to give motion properly' to the smaller bevel gear-wheel D' on lthe front end of the longitudinal shaft D, having a quicker rotation according to the difference in the size of the gears. The rear end of the shaft D carries a bevel gear-wheel D2, shown as a miter-bevel, which engages with a corresponding bevel gear-wheel E2 on the rear wheel E.

The longitudinal shaft D extends through a hollow portion M of the frame, corresponding Ato the ordinary iixed tube lying in that position, but there are certain peculiarities. Near the front end the tubular condition terminates, the further extension forward being formed first by a loop M of sufiicient size to afford ample room for the gear -wheel D'. Beyond this it is extended forward a little distance in a solid or tubular form M2., the front portion of which is cut away on. the under side, so as to make it only half-cylindrical. This portion of the framing extends still farther forward, all integrally, the forward portion being arched or bent in a semicircle Mterminatingin a knuckle M4. A correspondingly-curved piece P is joined to the knuckle M4 and can turn thereon. These two `parts thus knuckled together form a clamp the interior of which is accurately matched to the exterior of the cross-tube A of the frame, so that it may rmly embrace it. A short length P' at the rear end of the part I? stands radially to the curve and is semicylindrical in cross-section. The exteriors, both of the parts M2 and P', are screw-threaded and slightly tapered, small end rearward. They receive a nut Q, which on being screwed v forward upon the matched semicylindcrs M2 and P hold the clamp tightly closed. In this condition these portions of the framing are firmly united and mutually supported. On the nut Q being turned to carry it sufiiciently rearward it leaves the part P free and allows the clamp to be opened.

IOO

The nearly horizontal tube M is not exactly at right angles to the cross-tube A and its inclosed shaft B. The interiors of the curved portions M3 and P of the clamp are bored or otherwise truly finished with a corresponding degree of obliquit-y. This clamp will match accurately and take a rm hold on the exterior of the adjacent portion of the tube A, with capacity to be slackened and adj usted laterally to a considerable extent thereon to allow the depth of the engagement of the teeth of the bevel-wheels B and D to be accurately adjusted.

M5 is a rigidly-attached arm extending horizontally inward from the tube M at the point represented. Its under surface is finely toothed and adapted to engage with a correspondingly-toothed arm A2, extending horizontally inward from the opposite nearly horizontal longitudinal frame-tube A. A clamp Nembraces these arms M5 and A2 and holds them stifiiy united in any required position.

When for any reason, as the wear or the springing or bending of any part, the teeth of the bevel gear-wheels B and D do not engage sufliciently deep, the grip of the parts M3 and P on the tube A is relaxed, the clamp N is slackened by turning a set-screw, (not shown,) and when the proper adjustment of position is attained the parts are again tightened, so as to make the connections rigid and very strong.

At the rear end of the horizontal tube M are wings M5, fixed firmly thereon. The main frame is formed at this point as an open loop A3, having an open space at the front. The wings M6 bridge across the open front and apply above and below, as shown, and are held stiffly by screw-bolts L and nuts L. (See Figs. 6 and 7.) The framing A4 holds the loop A3 and wings M6, and also performs the ordinary functions of this portion of the framing by making a strong and reliable connection tothe lixed axis R of the rear wheel (see Fig. 3) and extending upward integrally to form the inclined brace G, held by a screw to the framing adjacent to the saddle-post in the ordinary manner.

An arm G extends horizontally inward from the inclined frame-piece G above the wheel E. A correspondinginclined frame piece or brace H extends up on the opposite (the left) side of the bicycle, provided with an arm H', which is the counterpart of the arm G and matches to it. These arms G and I-I are united by the aid of a clamp I, which is tightened and relaxed by a screw. This strongly and rigidly supports the said parts and allows their easy separation when required.

This construction facilitates the removal of the longitudinal shaft D and its attachments when it is necessary for cleaning or for repair or exchange. I can by making a still greater change of position of this shaft allow of changing the gears, substituting, for example, a smaller bevel-wheel B and a larger bevelwheel D, and thus correspondingly lowering the gear. This requires simply shifting the clamp M3 P on the fixed cross-tube A, and correspondingly shifting the parts A2 and M5 relatively to each other. The change in the angular position of the frame M, to thus make a considerable difference in the gearing at the front, will not ordinarily involve any appreciable difculty. The tightness of the grip of this ring-clamp in the required position on the xed cross-tube A may be increased by ordinary means, as a set-screw tapped through either of the parts. Fig. 5 shows such a screw inserted through the hinged limb P at the lowest point.

J is a casing of thin metal properly formed and applied to inclose the gear-wheels B D at the front. A corresponding, but smaller, casing K incloses the wheels D2 and E2 at the rear.

Modifications may be made without departing from the principle or sacrificing the advantages of the invention. I can bend the front portion at the junction of the arch M6, so that the clamp M3 P will take hold of the tube A in a position more nearly or exactly at right angles to the axis of the latter.

I claim as my invention- 1. In a bicycle operating by a longitudinal shaft D, extending through the tubular framepiece M, a split clamp at the front end allowing of engagement and disengagement with the cross-tube A and also of lateral adjustment thereon, substantially as herein specihed.

IOO

2. In a bicycle operating by a longitudinal shaft D, extending through the tubular framepiece M, a detachable clamp at the front end allowing of engagement and disengagement with the cross-tube A, in combination with the bracing-arms M5, A3, and clamp N, adapted to allow the convenient assemblage and separation of the parts and also the adjustment of the engagement of the gear-wheels B, D, all substantially as herein specified.

` 3. In a bicycle operating by a longitudinal shaft D, extending through the tubular framepiece M, a split clamp at the front end allowing of lateral adj ustment upon and also of engagement and disengagement with the crosstube A and the open yoke A3, wings M6 and fastening means L, adapted to allow a strong and rigid connection and an easy disconnec- IIO tion and removal or change of position rela- JOHN MCLEAN.

Witnesses:

J. B. CLAUTICE, M. F. BOYLE.

Y mk Y n 

